src/mem/external_slave.cc

   1 /*
   2  * Copyright (c) 2012-2014 ARM Limited
   3  * All rights reserved
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * Authors: Andrew Bardsley
  38  */
  39
  40 #include "mem/external_slave.hh"
  41
  42 #include <cctype>
  43 #include <iomanip>
  44
  45 #include "base/trace.hh"
  46 #include "debug/ExternalPort.hh"
  47
  48 /** Implement a `stub' port which just responds to requests by printing
  49  *  a message.  The stub port can be used to configure and test a system
  50  *  where the external port is used for a peripheral before connecting
  51  *  the external port */
  52 class StubSlavePort : public ExternalSlave::ExternalPort
  53 {
  54   public:
  55     void processResponseEvent();
  56
  57     EventFunctionWrapper responseEvent;
  58
  59     /** Stub can handle a single request at a time.  This will be
  60      *  NULL when no packet is in flight */
  61     PacketPtr responsePacket;
  62
  63     /** Received a new request while processing a first.  Need to ask for
  64      *  a retry after completing this packet */
  65     bool mustRetry;
  66
  67     StubSlavePort(const std::string &name_,
  68         ExternalSlave &owner_) :
  69         ExternalSlave::ExternalPort(name_, owner_),
  70         responseEvent([this]{ processResponseEvent(); }, name()),
  71         responsePacket(NULL), mustRetry(false)
  72     { }
  73
  74     Tick recvAtomic(PacketPtr packet);
  75     void recvFunctional(PacketPtr packet);
  76     bool recvTimingReq(PacketPtr packet);
  77     bool recvTimingSnoopResp(PacketPtr packet);
  78     void recvRespRetry();
  79     void recvFunctionalSnoop(PacketPtr packet);
  80 };
  81
  82 class StubSlavePortHandler : public
  83     ExternalSlave::Handler
  84 {
  85   public:
  86     ExternalSlave::ExternalPort *getExternalPort(
  87         const std::string &name_,
  88         ExternalSlave &owner,
  89         const std::string &port_data)
  90     {
  91         StringWrap name(name_);
  92
  93         DPRINTF(ExternalPort, "finding stub port '%s'\n", port_data);
  94         return new StubSlavePort(name_, owner);
  95     }
  96 };
  97
  98 Tick
  99 StubSlavePort::recvAtomic(PacketPtr packet)
 100 {
 101     if (DTRACE(ExternalPort)) {
 102         unsigned int M5_VAR_USED size = packet->getSize();
 103
 104         DPRINTF(ExternalPort, "StubSlavePort: recvAtomic a: 0x%x size: %d"
 105             " data: ...\n", packet->getAddr(), size);
 106         DDUMP(ExternalPort, packet->getConstPtr<uint8_t>(), size);
 107     }
 108
 109     return 0;
 110 }
 111
 112 void
 113 StubSlavePort::recvFunctional(PacketPtr packet)
 114 {
 115     recvAtomic(packet);
 116 }
 117
 118 void
 119 StubSlavePort::processResponseEvent()
 120 {
 121     responsePacket->makeResponse();
 122     responsePacket->headerDelay = 0;
 123     responsePacket->payloadDelay = 0;
 124
 125     if (sendTimingResp(responsePacket)) {
 126         responsePacket = NULL;
 127
 128         if (mustRetry)
 129             sendRetryReq();
 130         mustRetry = false;
 131     }
 132 }
 133
 134 bool
 135 StubSlavePort::recvTimingReq(PacketPtr packet)
 136 {
 137     if (responsePacket) {
 138         mustRetry = true;
 139
 140         return false;
 141     } else {
 142         recvAtomic(packet);
 143
 144         responsePacket = packet;
 145         owner.schedule(responseEvent, curTick());
 146
 147         return true;
 148     }
 149 }
 150
 151 bool
 152 StubSlavePort::recvTimingSnoopResp(PacketPtr packet)
 153 {
 154     fatal("StubSlavePort: function: %s\n", __func__);
 155     return false;
 156 }
 157
 158 void
 159 StubSlavePort::recvRespRetry()
 160 {
 161     assert(responsePacket);
 162     /* Stub handles only one response at a time so responseEvent should never
 163      *  be scheduled at this point.  Retrys shouldn't need to schedule, we
 164      *  can safely send the response here */
 165     responseEvent.process();
 166 }
 167
 168 void
 169 StubSlavePort::recvFunctionalSnoop(PacketPtr packet)
 170 {
 171     fatal("StubSlavePort: unimplemented function: %s\n", __func__);
 172 }
 173
 174 std::map<std::string, ExternalSlave::Handler *>
 175     ExternalSlave::portHandlers;
 176
 177 AddrRangeList
 178 ExternalSlave::ExternalPort::getAddrRanges() const
 179 {
 180     return owner.addrRanges;
 181 }
 182
 183 ExternalSlave::ExternalSlave(ExternalSlaveParams *params) :
 184     MemObject(params),
 185     externalPort(NULL),
 186     portName(params->name + ".port"),
 187     portType(params->port_type),
 188     portData(params->port_data),
 189     addrRanges(params->addr_ranges.begin(), params->addr_ranges.end())
 190 {
 191     /* Register the stub handler if it hasn't already been registered */
 192     if (portHandlers.find("stub") == portHandlers.end())
 193         registerHandler("stub", new StubSlavePortHandler);
 194 }
 195
 196 Port &
 197 ExternalSlave::getPort(const std::string &if_name, PortID idx)
 198 {
 199     if (if_name == "port") {
 200         DPRINTF(ExternalPort, "Trying to bind external port: %s %s\n",
 201             portType, portName);
 202
 203         if (!externalPort) {
 204             auto handlerIter = portHandlers.find(portType);
 205
 206             if (handlerIter == portHandlers.end())
 207                 fatal("Can't find port handler type '%s'\n", portType);
 208
 209             externalPort = portHandlers[portType]->getExternalPort(portName,
 210                 *this, portData);
 211
 212             if (!externalPort) {
 213                 fatal("%s: Can't find external port type: %s"
 214                     " port_data: '%s'\n", portName, portType, portData);
 215             }
 216         }
 217         return *externalPort;
 218     } else {
 219         return MemObject::getPort(if_name, idx);
 220     }
 221 }
 222
 223 void
 224 ExternalSlave::init()
 225 {
 226     if (!externalPort) {
 227         fatal("ExternalSlave %s: externalPort not set!\n", name());
 228     } else if (!externalPort->isConnected()) {
 229         fatal("ExternalSlave %s is unconnected!\n", name());
 230     } else {
 231         externalPort->sendRangeChange();
 232     }
 233 }
 234
 235 ExternalSlave *
 236 ExternalSlaveParams::create()
 237 {
 238     return new ExternalSlave(this);
 239 }
 240
 241 void
 242 ExternalSlave::registerHandler(const std::string &handler_name,
 243     Handler *handler)
 244 {
 245     portHandlers[handler_name] = handler;
 246 }